Cover and switch interlock



Sept. 20, 1966 Y D. F. DALY ETAL 3,274,353

COVER AND SWITCH INTERLOCK Original Filed Jan. 14. 1960 I i s Sheets-Sheet 1 ml/ e37 fors F/ 6. 2 00/7/6/ F [704/ Joseph /I//. 0 M0//e=y By f/re/r offomeys Sept. 20, 1966 D F. DALY ETAL 3,274,353

1 COVER AND SWITCH INTERLOCK Original Filed Jan. 14, 1960 5 Sheets-Sheet 2 //7l//7/0/5 00/7/29/ F 004/ Joseph M 0M0//ey By f/ze/r af/omeys WQMM D. F. DALY ETAL.

COVER AND SWITCH INTERLOCK Original Filed Jan. 14, 1960 Sept. 20, 1966 5 Sheets-Sheet. 2;

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United States Patent 3,274,353 COVER AND SWITCH INTERLOCK Daniel F. Daly, Newington, and Joseph M. OMalley, West Hartford, Conn., assignors to The Arrow-Hart & Hegeman Electric Company, Hartford, Conn., a corporation of Connecticut Continuation of application Ser. No. 2,395, Jan. 14, 19 60. This application June 5, 1963, Ser. No. 286,443 9 Claims. (Cl. 200-50) This application is a continuation of our application Ser. No. 2,395, filed Jan. 14, 1960, now abandoned.

This invention relates to electric switches housed within covered boxes and more particularly to means for locking a switch in various positions under predetermined conditions and to release it for operation and for opening of the cover or under other conditions such as in emergencies or for inspection.

One object of the invention is to provide an improved electric switch mechanism which cannot be operated from open to closed-position while the cover is open.

Another object is to provide means to lock the cover closed when the switch is closed, but to allow the cover to be opened by authorized personnel with the switch closed.

Another object to provide a switch having the foregoing characteristics, with means for absolute locking (as for example by a padlock) in open-position and preventing either it to be moved closed or the cover to be moved open when so locked, notwithstanding the presence of the otherwise operable means to permit authorized personnel to open the cover.

Another object is to provide an enclosed switch having the aforesaid characteristics which is operable between open and closed-positions with a snap action and is biased into its open and closed positions.

Another object is to provide a switch and box combination having the aforesaid characteristics, with means to position the handle in a normal-open and a normalclosed-circuit position, but to allow movement beyond the normal-open position for absolute locking of the switch open and the cover closed.

Other objects and advantages of the invention will occur to those skilled in the art as the invention is described in connection with the accompanying drawings.

In the drawings:

FIG. 1 is a side elevation view, partly broken away, of an enclosed switch operating mechanism embodying the invention with the mechanism in off position.

FIG. 2 is a view similar to FIG. 1 with the switch mechanism in position to be locked open and the cover locked closed. a

FIG. 3 is an end elevation view, partly broken away, of the operating mechanism with the box shown in transverse section.

FIG. 4 is an exploded perspective view, partly broken away, of the main operating parts. and switch-contactoperating bail.

FIG. 5 is a side elevation view from the right of FIG. 3 of the operating parts with the box omitted.

FIG. 6 is a fragmentary phantom perspective view showing in full lines the parts attached to the cover and in phantom the cover box and latch lever.

FIG. 7 is a side elevation view, partly broken away, of the switch as illustrated in FIGS. 1 and 2, but with the mechanism in the switch on or closed position and with the cover locked.

Referring to the drawings, the switch contacts and operating mechanism may be mounted in a conventionally shaped rectangular sheet metal switch box 10. The fixed and movable contacts may be of any suitable type 3,274,353 Patented Sept. 20, 1966 such for example as in pivoted knife-blade switches. For simplicity, the contacts are omitted from the drawings.

CONTACT-OPERATING AND HANDLE- POSITIONING MEANS The contacts may be operated by a U-shaped bent wire rod or bail 12 which is mounted for pivotal movement about an axis parallel to the transverse part of the bail with one end outturned to extend through a bearing hole inthe side of the box while the other is pivotally supported from a stud shaft 14, which, in turn, is supported in a bearing bracket 20 afiixed to the opposite wall of the box.

The bearing bracket is stamped from sheet metal into U-shaped with a plate portion 21 on one side and two wing portions 22 on the other, parallel to the plate portion 21. The wing portions are bolted against the side of the box. A bearing aperture is provided in the plate portion through which the stud shaft 14 passes. On the stud shaft is a sleeve on which is pivotally mounted a drive plate 24 between the wing portions and the plate portion 21 and flush against the latter. The drive plate is stamped from sheet metal and is generally in the shape of a quarter segment having extensions 25 and 26 at each of its opposite ends.

The drive plate is provided with a peripheral recess between its extensions 25 and 26 providing shoulders 27 and 28 to engage the opposite ends of a lug 16 bent normally to the plane of a stamped sheet metal actuating arm 18 which is allixed to the bail 12. As the drive plate 24 is moved in clockwise or counterclockwise direction, by the overcenter-actuating mechanism hereinafter described, one shoulder 27 or the other 28 will strike against the lug 16 and move the arm 18 and the bail 12 as a unit to operate the movable switch contacts.

' To the corner of one extension 26 of the drive plate is pivotally attached a T-shaped bar or spring retainer 29 through the central portion of whose head passes a rivet to secure the retainer pivotally to said extension. Impaled on the retainer is one end of a coiled compression over-center spring 30 whose other end is pivotally anchored on a pin 31 on the side of the box 10.

In order to operate the switch, an operating lever or handle 40 is provided outside of the box and is pivotally mounted in the side of the box by the following means.

The handle is connected by securing screws to a member 46 which is within the box and lies against the inside surface of the box. The screws pass through holes in a handle-spacing washer 42, which lies outside of but flush against the box wall, and through registering holes in a bearing washer 44, which rotates in a bearing aperture in the box wall. The member 46 serves both for actuating the drive plate 24 and also for locking the handle when the box cover 10c is open. The member 46 is generally of disc-shape with a portion of the periphery extended to alford an elevated cam surface 49 .while another portion of the periphery at the end of the cam surface is recessed or inwardly out toward the center 'member providing a notch 47 to receive the nose of a latch, as hereinafter described.

To actuate the drive plate, the actuating member 46 has a radially extending actuating lug 4'8 turned at right angles from its periphery. This lug extends toward the drive plate 24 and into its recess, but at a location nearer the axis of rotation than the lug 16 of the bail-actuating arm 18 so as to pass under the lug 16.

Forpositioning the handle and the member 46 which move as a unit therewith, relative to the drive plate 24, there is affixed to the drive plate by welding or any other suitable manner a centering member 32 generally of discshape with a radial extension 33 that is bent at .a right angle away from drive plate 24. Wound around the stud shaft sleeve is a spirally coiled spring 34 having its ends outturned substantially in radial directions and adapted to lie on opposite sides of both the bent end 33 of the centering member 32 and of the actuating lug or actuating member 46.

As the handle is rotated in one direct-ion, one end of the spiral spring 34 will be turned while the other end remains stationary until the actuating lug 48 abuts against one of the shoulders 27 or 28 of the drive plate 24. Thereafter, the actuating lug 48 will rotate the drive plate 24 which, being connected to the overcenter spring 30, will start to move the overcenter spring toward deadcenter position. Ultimately upon reaching the dead-center position, the overcenter spring will reverse its direction of action and will snap the drive plate 24 toward its other position.

In the course of this movement, the shoulder 27 or 28 will strike against the lug 16 of the bail-actuating arm 18; and since the arm 18 and the bail rotate as a unit about the axis of the stud shaft, they are jointly operated to operate the switch.

To limit the movement of the bail, the edge of the side-plate-portion 21 of the bearing bracket 20 is recessed from the top toward the stud shaft 14, and the two upstanding ends thus formed are offset inwardly affording stops 21s at the opposite ends of the permitted travel of the bail-actuating arm 18. This limits the travel of the bail so as to properly locate the switch blades with reference to the switch contacts (not shown).

The bail may be resiliently mounted and pressed (together with its actuating arm 18) toward the operating assembly by a compression spring 15 coiled on the opposite end of the bail from the handle. This spring presses against the shoulder bend on the bail at one end and against the side wall of the box at its other. This enables the b-ail and switch arm assembly to be easily assembled in the box and in connection with the operating mechanism or removed therefrom as occasion may require. 1

Referring to FIG. 1, it will be noted that the effor of the overcenter spring 30 urges the drive plate 24 counterclockwise causing its shoulder 27 to also press lug 16 of the bail-actuating arm 18 counterclockwise until stopped by the bearing bracket 20. The handle, meantime, is centered with respect to the drive plate 24 by the ends of the spiral spring 34 acting on opposite sides of the lugs 33 and 48. In that way, the locking and actuating member 46 is held as shown in FIG. 1 in position for the notch 47 to receive the nose of the latching lever 50, as will now be described.

COVER AND SWITCH INTERLOCKING MEANS (a) Prevention of switch-closing with box cover open When the switch is in off position and the box cover is open, it is desirable to prevent the handle from being operated to throw the switch into on position. For this purpose, a flat metal latch lever 50 is pivotally mounted on a pin 51 in the side wall of the box. Preferably this latch lever is mounted and contained between two plate members 52, 53 which form a housing or enclosure for the latch lever. These members may be stamped from sheet metal and secured together in spaced relation and with one plate 52 against the side wall of the box by means of screws or rivets passing therethrough. Flanges 5311 are provided on the other enclosure memher to space it from the other and from the side wall of the box.

The latch lever has a nose 55 which is adapted to engage in the notch 47 in the locking member 46 when the switch is in open-circuit position and the cover is open. When the cover is closed, however, the nose 55 is withdrawn as is shown in FIG. 1 so that the switch can be operated.

In order to insure or cause movement of the nose into the notch when the cover is open, a biasing hairpin type spring 56 is provided. This spring is wound around a rivet or other suitable pivot 57 and one end presses against the flange 53a of the latch-and-spring housing while the other end presses against the back of the latch lever 50.

'In order to withdraw the latch nose when the cover is closed, a finger 58 having an inclined cam surface on the edge thereof nearest the cover is provided on the latch lever in position to be engaged by a catch bar 60 carried by the cover of the box. As the cover closes, the catch bar 60 engages the inclined surface of the finger and causes the latch lever to pivot counterclockwise and its nose to move out from the handle to the position shown in FIG. 1. This releases the mechanism and permits movement of the switch from open to closed position when desired.

The catch bar 60 which is rectangular in cross-section is mounted in a stamped sheet metal bracket 70 formed as shown in FIG. 6 with a U-shaped portion 72 having parallel legs 71 and 73 in which are rectangular apertures through which the bar passes, transversely, normal to -the side wall of the box and with its ends projecting beyond the legs. The end nearest the box will engage at its lower edge 'with the latch lever to pivot it when the cover closes as above described.

As the switch moves from open position of FIG. 1 to closed position of BIG. 7, the notch of the lockingand-actu'ating member 46 moves from the path of the latch nose and, thereafter, the periphery of the member 46 lies in the way of the latch lever and prevents movement of the latch lever. As a result of this and by reason of the provision of a second finger or hook 59 on the latch lever hooking over the catch bar 60, the cover of the box must remain latched-closed, so long as the hook 59 overlies the catch bar.

(b) Authorized cover-opening with switch closed If it should be desired for authorized personnel to open the cover with the swtich in closed position, this can be accomplished by the provision of an aperture 66 in the flange of the box cover and by mounting the catch bar 60 resiliently in the bracket 70 in such a manner as to permit it to be pressed inwardly out of the plane of the hook 59 when an implement is inserted through the aperture and pressed against the catch bar. To enable that to be done, a spring 62 is wound around the catch bar 60, one end of which presses against one leg 73 of the bracket while the other end presses against a transverse pin 64 driven into the catch bar. A slot or recess 67 is provided in the upper edge of the box in line with the catch bar so that the implement will not be impeded as it moves up with the cover during the initial movement of the cover from the box after pressing the bar against its biasing spring sufficiently to disengage the bar from the latch lever hook 59.

Since the finger 58 is clear of the hereinafter described catch lug 74 on the cover as the cover is lifted, and since the catch bar is pushed in and, thus, withdrawn from the plane of the hook 59, the cover can be opened without impediment.

In order to be able to reclose the cover while the switch is still closed, the end of the catch bar is beveled so that when it butts against the hook 59, the catch bar will, by a camming action, compress spring 62. This will allow the catch bar to snap in back of the hook when the cover is closed and thus to again latch the cover. The reclosing of the cover and relatching it occurs without affecting the position of the switch or the operating mechanism.

(c) Padlocking of switch open with cover closed In order to be able to lock the switch in open-circuit position with the cover latched shut so that the box cannot be entered nor the switch operated under any circumstances, there is provided on the outside of the box an S-shaped stamped sheet metal padlock bracket 80, one leg of which is afiixed against the side of the box, while the other leg has one or more holes to receive the hasp of a padlock. A suitable elongated aperture is provided in the switch handle to receive the padlock hasp.

In normal open or off position, the handle is spaced from the S-shaped locking bracket as shown in FIG. 1. But, the handle may be moved from the FIG. 1 position into abutment with the S-shaped bracket as in FIG. 2, by reason of the movability of the end of the handle-positioning spring 34. The lug 48 on the actuating member 46 moves this end of the spring when the handle is moved from normal oif position to absolute locking position. When the handle is moved from normal ofi position to absolute locking position, the latch lever 50 is caused to pivot in counterclockwise direction from the position of FIG. 1 to FIG. 2 by the peripheral cam extension 49 on the periphery of the actuating member 46, camming against the round portion of the nose of the latch lever 50. Thus, the latch lever is held in the position indicated in FIG. 2. In such position, both the finger 58 and the hook 59 on the other end of the latch lever function to hold the cover closed. The hook 59 engages with a catch bar 60 while the finger 58 engages with a fixed catch lug 74 which may conveniently be formed as an intergral part extending from the bracket 70 on the cover.

In case the latch lever biasing spring 56 should break or fail to function, provision is made for the catch bar 60 to positively push the latch lever in the same direction as the spring bias when the switch is open and the cover opens. This is accomplished by inclining the inner edge of the hook 59 so that as the latch bar 60 engages it as the cover opens, the lever will be caused to pivot clockwise (FIG. 1).

Form the foregoing, it will be observed that the invention provides:

(a) For latching the switch open when the cover is open.

(b) For allowing closing and opening of the switch when the cover is closed.

(c) For latching the cover closed when the switch is closed.

(d) For allowing authorized personnel to open the cover in an emergency or for inspection while the switch is closed and to reclose the cover without disturbing the switch.

(e) For disabling the emergency-authorized coveropening means when the switch is locked (as by a padlock) in past-open position with the cover closed.

(15) For accomplishing all the foregoing in an overcenter or snapopen-and-closed switch.

Modifications within the scope of the invention will occur to those skilled in the art. Therefore, the invention is not limited to the specific form and configuration of parts shown and described.

What is claimed is:

1. The combination of electric switch operating mechanism with a box having an openable cover, comprising a pivoted contact-operating means within the box, manual actuating means operable from outside the box and separate from and movable independently of said contact-operating means, snap-action means actuated by said manual actuating means for snap action from one position to another and moving said contactoperating means from one position to another, movable latching means mounted on the box engaging with said manual actuating means when the cover is open to prevent operation of the manual actuating means in one direction, movable means on the cover engaged by the latching means While the cover is closed and While the manual actuating means is in one position to latch the cover closed, and means operable from the outside of the box to move said movable means while said latching means remains stationary and while the manual actuating means remains in said one position, to unlatch the cover.

2. The combination of electric switch operating mechanism with a box having a openable cover, comprising a pivoted contact-operating means within the box, manual actuating means operable from outside the box and separate from and movable independently of said contact-operating means, snap-action means actuated by said manual actuating means for snap action from one position to another and moving said contact-operating means from one position to another, movable latching means mounted on the box engaging with said manual actuating means when the cover is open to prevent operation of the manual actuating means in one direction, and means on the cover engaged by the latching means to latch the cover closed while the manual actuating means is in one position, said means-on-the-cover being movable from outside the cover out of the plane of said latching means to unlatch the cover while the latching means remains stationary and while the manual actuating means remains in said one position.

3. The combination as claimed in claim 1 having means to bias the manual actuating means in said one position thereof and also in another position, said manual actuating means being movable past said other position, said manual actuating means being movable past said other position to a third position against said biasing means in which it may be locked.

4. The combination of electric switch operating mechanism with a box having an openable cover, comprising contact operating means within the box movable between two positions, means including manual operating means operable from outside the box to operate said contact operating means, latching means entirely within the box operable by said manual operating means, said latching means and said manual operating means being movable into three positions, means on the cover engaged by said latching means to hold the cover closed when said manual operating means and said latching means are in one position, and other means on said cover and latching means whereby said manual operating means upon movement into a third position operates said other means to hold said cover closed while said manual operating means and said latching means are in said third position.

5. The combination of electric switch operating mechanism with a box having an openable cover, comprising contact-operating means within the box, means including manual operating means operable from outside the box movable between two positions, latching means inside the box operable by said manual operating means, said latching means and said manual operating means being movable into three positions, means on the cover engaged by said latching means to hold the cover closed when said manual operating means and said latching means are in one position, means operable from outside the box while said manual operating means remains in said one position to disengage said latching means to permit openng of the cover, and other means on said cover and latching means whereby said manual operating means upon movement into a third position operates said other means to hold said cover closed while said manual operating means and said latching means are in said third position irrespective of operation of said latch-disengaging means, so long as said manual operating means remains in said third position.

6. The combination of electric switch operating mechanism with a :box having an openable cover, comprising a pivoted contact-operating means within the box, a bracket attached to the interior of the box, a pivotal connection between said bracket and said contact-operating means, manual operating means pivotally mounted in the wall of the box and operable from outside the box and separate from said contact-operating means, drive means mounted pivotally on said bracket operable by said manual operating means and operating said contactoperating means, snap acting means within said box causing said contact-operating means to move from one position to another when said manual operating means has moved a predetermined amount, positioning means within said box separate from said snap acting means acting on said manual operating means and said drive means to position the one with relation to the other, latching means within said box controlled by said manual operating means in one position of the latter to hold the cover closed and holding said latter in another position from operation to said one position while the cover is open.

7. The combination claimed in claim 6 in which the positioning means comprises a coiled spring with ends engaging both the manual operating means and the drive means.

8. The combination of electric switch operating mechanism with a box having an openable cover, comprising a pivoted contact-operating means within the box, manual actuating means operable from outside the box and separate from and movable independently of said contactoperating means, snap-action means within said box actuated by said manual actuating means for snap action from one position to another and moving said contact-operating means from one position to another, latching means mounted on the interior of the box engaging with said manual actuating means when the cover is open to prevent operation of the manual actuating means in one direction, means on the cover engaged by the latching means while the cover is closed and while the manual actuating means is in one position to latch the cover closed, means operable from the outside of the box and while the manual actuating means remains in' said one position to unlatch the cover, and means to bias the manual actuating means in said one position thereof and also in another 7 position, said manual actuating means being movable past 9. The combinationof electric switch operating mechanism with a box having an openable cover, comprising a pivoted contact-operating means within the box, manual actuating means operable from outside the box and separate from and movable independently of said contactoperating means, snap-action means actuated by said manual actuating means for snap action from one position to another and moving said contact-operating means from one position to another, latching means mounted on the box engaging with said manual actuating means when the cover is open to prevent operation of the manual actuating means in one direction, means on the cover engaged by the latching means while the cover is closed and while the manual actuating means is in one position to latch the cover closed, means operable from the outside of the box and while the manual actuating means remains in said one position to unlatch the cover, and means to bias the manual actuating means in said one position thereof and also in another position, said manual actuating means being movable past said other position to a third position against said biasing means in which it may be locked, and means on the latching means and cover to hold the cover closed irrespective of operation of said means-to-unlatch the cover from the outside, so long as said actuating means remains in said third position.

References Cited by the Examiner UNITED STATES PATENTS 1,444,556 2/1923 Sachs 200-67 X 1,483,715 2/1924 Burns 200-5() 1,568,042 1/1926 Broad'well 200-50.1 1,715,339 5/1929 Widmer 20050.l 2,108,883 2/1938 Furnas et al. 200-468 2,472,961 6/1949 Scott 200169 ROBERT K. SCHAEFER, Primary Examiner.

ROBERT Kr SCHAEFER, KATHLEEN H. CLAFFY,

Examiners. M. GINSBURG, Assistant Examiner. 

4. THE COMBINATION OF ELECTRIC SWITCH OPERATING MECHANISM WITH A BOX HAVING AN OPENABLE COVER, COMPRISING CONTACT OPERATING MEANS WITHIN THE BOX MOVABLE BETWEEN TWO POSITIONS, MEANS INCLUDING MANUAL OPERATING MEANS OPERABLE FROM OUTSIDE THE BOX TO OPERATE SAID CONTACT OPERATING MEANS, LATCHING MEANS ENTIRELY WITHIN THE BOX OPERABLE BY SAID MANUAL OPERATING MEANS, SAID LATCHING MEANS AND SAID MANUAL OPERATING MEANS BEING MOVABLE INTO THREE POSITIONS, MEANS ON THE COVER ENGAGED BY SAID LATCHING MEANS TO HOLD THE COVER CLOSED WHEN SAID MANUAL OPERATING MEANS AND SAID LATCHING MEANS ARE IN ONE POSITION, AND OTHER MEANS ON SAID COVER AND LATCHING MEANS WHEREBY SAID MANUAL OPERATING MEANS UPON MOVEMENT INTO A THIRD POSITION OPERATES SAID OTHER MEANS TO HOLD SAID COVER CLOSED WHILE SAID MANUAL OPERATING MEANS AND SAID LATCHING MEANS ARE IN SAID THIRD POSITION. 